1. Field of the Invention
Apparatuses and methods consistent with the exemplary embodiments relate to a medium supply unit to supply a printing-target medium to an image forming unit of forming an image; and an image forming apparatus having the same, and more particularly, to a medium supply unit in which the assembly structure of a pickup roller assembly to pick up and supply loaded printing-target media is improved and; and an image forming apparatus having the same.
2. Description of the Related Art
An image forming apparatus can form a visual image by a developing solution or an ink on a printing-target medium based on image data supplied from an external host apparatus. To that end, the image forming apparatus includes an image forming unit and a medium supply unit which supplies a printing-target medium to the image forming unit.
In the medium supply unit of the image forming apparatus, a plurality of printing-target media are loaded in a loading cassette that is attachable to a housing of a main body thereof or in a loading tray that is pivotable with respect to the housing. The loaded printing-target media are picked up by a pickup roller to be supplied to the image forming unit.
Such a pickup roller is made of a material having a high frictional coefficient, such as a synthetic rubber, and rotatable while being brought into contact with the printing-target media with a predetermined pressure to pick up the printing-target media by a frictional force therebetween. Accordingly, if the pickup roller is used for a long period of time, a surface of the pickup roller is worn out by such friction, thereby lowering the picking-up performance thereof. Therefore, there is a requirement to replace the old pickup roller with a new one in adequate intervals.
In the meantime, the old pickup roller is required to be separated from an activating shaft, used to rotate the pickup roller, to be replaced with a new one. Since, however, the activating shaft penetrates through the pickup roller in such a conventional medium supply unit, the activating shaft and the pickup roller are required to be separated together from a main body of the image forming apparatus in order to replace the pickup roller. In this case, the time that it takes to replace the pickup roller is increased because the assembly structure of the pickup roller in the main body thereof is complex.